硅对铝胁迫下甘蔗幼苗的缓解效应研究

Alleviating effects of silicon on sugarcane seedlings under aluminum stress

铝毒是酸性土壤地区普遍存在的实际问题,如何解决铝毒对作物的伤害是一个难点。采用营养液培养法,通过测定分析铝胁迫条件下不同浓度硅处理对甘蔗幼苗生长及生理指标的变化,研究硅对甘蔗幼苗铝毒的缓解效应。结果表明,铝胁迫处理（T1）与空白对照相比,甘蔗株高和干物质量显著下降,根系形态参数包括根总长、根直径、根体积和根表面积显著减少,根系活力、叶片SPAD值和超氧化物歧化酶（SOD）显著降低,丙二醛（MDA）含量和电导率显著升高,说明铝胁迫下,甘蔗植株的正常生长和生理活动均受到损害;而向营养液中添加1～2mmol/L硅酸钠处理（T2、T3）,相比T1处理,甘蔗株高、干物质量显著增加,根系形态各项参数得到显著改善,甘蔗根系活力和叶片SPAD值显著提高,叶片丙二醛含量和电导率显著降低,表明硅能有效缓解铝对蔗苗的毒害。

Aluminum （Al） toxicity is a practical problem in the acid soil area of Southern China,and is not easy to solve it for crops. In this paper,the effects of silicon on the growth and physiological indexes of sugarcane seedlings with different SiO_3^（2-） treatments under Al^（3＋） stress were studied by using the nutrient solution culture. Results showed that under the Al stress （T1）,compared with the normal （CK）,all of the plant height,dry weight,root length,root diameter,root volume and root surface area decreased significantly. Similarly,root activity,leaf SPAD value and superoxide dismutase （SOD） decreased significantly. But the content of malondialdehyde （MDA） and electrical conductivity increased significantly. It indicated that the normal growth and physiological activity of sugarcane plants were damaged under aluminum stress. While with a range of 1-2 mmol/L sodium silicate solution added to the nutrient solution,compared to T1,both the plant height and dry matter weight increased,root morphology parameters were significantly improved,and root activity and leaf SPAD value also increased significantly,yet MDA content and electric conductivity decreased significantly. It indicated that silicon could effectively relieve aluminum toxicity on sugarcane seedling.